This invention relates to a gear arrangement for domestic use, particularly for kitchen appliances, having an input shaft at the driving end and an output shaft rotatably connected to a working part at the driven end, there being arranged between the input shaft and the output shaft a planet gear train comprising at least one planet gear, a sun gear meshing with said planet gear and a ring gear meshing with said planet gear, said planet gear being in meshing engagement with the input shaft on the one side and in rotary engagement by way of its axle bearing with the output shaft on the other side.
Planet gear trains, also referred to as epicyclic gear trains, are generally known and described in "Meyers Grosses Taschenlexikon", Volume 17, 1983, Bibliographisches Institut, Mannheim/Zurich or in "Meyers Lexikon der Technik und der exakten Naturwissenschaften", 3rd Volume, Bibliographisches Institut, Mannheim/Zurich, for example.
Planet gear trains are characterized in that at least one gear, called the planet gear, rotates not only about its own axis but also revolves with this axis around another gear, called the sun gear, and that, in addition, the planet gear meshes with this sun gear and an outer ring gear. If two of these three components, i.e., the planet gear, the sun gear and the ring gear, are held stationary, the third component executes a compulsory movement. Conventionally, use is made of three planet gears revolving around the sun gear and held in a common planet carrier. With the size of the individual gears suitably selected, it is possible to obtain commensurate speed increasing or speed reducing ratios between the input shaft and the output shaft, for example, between the shaft of the sun gear and the shaft of the planet carrier.
A planet gear train has already been used in a processing tool for preparing food, as disclosed in EP-B1 0 292 664. The processing tool known from EP-B1 0 292 664 is of the type used for mixing and kneading food ingredients. The processing tool comprises a working shaft adapted to be driven by an electric motor of a kitchen machine. The actual housing of the processing tool is shaped to serve simultaneously as the mixing and kneading tool. In the area of its upper end the housing is driven by way of a planet gear train, at its lower end it is in sliding contact with a bearing block. The upper end of the processing tool is rotatably held in a receiving container of the kitchen machine. In driving mode the housing, which serves simultaneously as the processing tool, is rotated by way of the planet gear train to perform a mixing and kneading movement.